What Is Posterior Urethral Stenosis?

Overview

Posterior urethral stenosis (PUS) is the narrowing of the urethra which reduces the flow of urine exiting your body. People can be born with PUS but it is rare. PUS is typically caused by an obstruction at your urethra either by receiving treatments for prostate cancer or trauma to the pelvis.¹ This condition can cause pain in your abdomen, urinary tract infections (UTI) and blood in your urine.

The importance of understanding PUS and the anatomy of the urethra can help guide healthcare professionals to make the appropriate decisions for patients regarding their treatment and care. Without receiving the appropriate care, you may find difficulty navigating your normal life due to unbearable symptoms and complications. 

Understanding the Urethra 

The urethra plays an important role in the normal functioning of the human body by allowing the excretion of waste products and excess fluids. 

The anatomy of the urethra is a hollow tube that varies in length in people assigned female at birth (AFAB) and people assigned male at birth (AMAB). Here is a comparison of the urethra in those individuals:

AFAB:

• Shorter urethra than AMAB individuals being only 4cm in length
• The primary function is the excretion of urine
• Embedded within the vagina wall

AMAB:

• Passes through the prostate gland and into the penis
• Approximately 18 to 20cm in length
• Carries both semen and urine but not at the same time²

Role in Urinary System

The urethra not only provides a passage for the expulsion of urine, but it also provides some protection against infections. The mucus lining in the urethra prevents the entry of bacteria. However, it can still be susceptible to infections. 

Causes 

The most likely causes of PUS may be having surgery or receiving high-energy therapies to treat prostate cancer.¹ Other causes could be trauma near the urethra and a tumour putting pressure on the urethra.

Symptoms and Signs 

Typical signs and symptoms of posterior urethral stenosis include:

• Blood in urine
• Pain while urinating
• Lower abdomen pain 
• Sense of incomplete emptying of the bladder
• The need to frequently urinate more than usual

If you are unable to urinate or feeling extreme pain, it's important to speak to your GP immediately so they can direct you to the best possible care.¹

Diagnosis

Various diagnostic tools are used to make an accurate diagnosis of posterior urethral stenosis. These include a medical history, physical examination and imaging tools.

Medical History and Physical Examination

Gathering a detailed medical history including, past surgeries, urinary problems or trauma can help identify the potential risk factors that could cause PUS. 

Uroflowmetry

Uroflowmetry is a diagnostic tool that measures the volume of urine, the speed at which it is released and how long it takes for the urine to be expelled out of the body. 

There are no risks associated with this procedure, you will be able to go home the same day you perform the test. 

You may be asked to halt your medication intake by your healthcare provider. This is to ensure it won’t affect your test results. To receive the most accurate results from your test, you must: 

• Not urinate at least 2 hours before the test
• Drink extra fluids

Signs someone may have PUS is extended urination time due to obstruction of the urethra. This means that it will take longer than usual to empty the bladder completely.³ 

This test does not tell us where the stenosis is located.

Ureteroscopy

Ureteroscopy is a medical examination that involves using a thin tube with a camera and light at its tip (ureteroscope) to examine the urethra and the bladder. This test is useful to allow clinicians to determine where the stenosis may be located. 

Complications with this procedure are rare with some people having a urine infection. In order to prevent this infection, you will receive antibiotics at the time of operation. 

Other imaging techniques

Ultrasound, X-rays and retrograde urethrogram are diagnostic tools that may be used to rule out other conditions like hydronephrosis, a condition where one or more of the kidneys swell up due to build-up of urine inside the kidneys.

Treatment Options for PUS 

The choice of treatment depends on the severity of the problem, the length and location of the stenosis, the patient’s overall health and how much scar tissue you have left. 

There is currently no medications that can treat and manage PUS. Without treatment, you will increase the chances of further complications such as urinary retention (unable to empty the bladder completely). Your treatment options may include dilating the stenosis, open surgery and urethrotomy.

Surgical Interventions

Endoscopic Procedures

Urethroscopy can also act as a therapeutic procedure by performing procedures like dilation (widening of the urethra) and removal of small stones.⁴

Dilation of stenosis is usually the first line of treatment for PUS. The results are immediate, quick and straightforward. An urologist will stretch the stenosis and ensure no tearing of the urethra.

Reconstruction Surgery

You may require reconstruction surgery if the extent of your stenosis is complex for dilation or the dilation procedure has failed. Your healthcare provider will discuss other options with you.

Urethrotomy

Reconstruction surgery, particularly urethrotomy,  is a procedure where urologists make incisions using special equipment (urethrotome) to open up the urethra. This allows the normal flow of urine to exit the body. 

This procedure may be repeated as the stenosis may reoccur. If there’s a high chance the stenosis will return after the operation, your healthcare provider may refer you to the Urology Nurse specialist so they can teach you how to dilate your urethra and keep it open. 

After surgery, you may feel sore and notice blood in your urine which is normal and will eventually settle. Possible complications of this procedure include erectile dysfunction with 2-10% of patients affected.⁵

Urethroplasty

Another type of reconstruction surgery that urologists may consider is urethroplasty. This procedure is considered to be the most effective treatment option for posterior urethral stenosis. Urethroplasty involves reconstructing the urethra by using grafts (using tissues from other parts of the body). Urethroplasty has a high success rate and was proven to be more cost-effective than long-term dilation.⁵

Complications and Risks Associated with PUS 

Complications associated with PUS include urinary tract infections (UTIs) and kidney disease, which may require antibiotics. It’s important to receive treatment for PUS immediately to avoid further complications.

If you’re diagnosed with PUS, you may experience a wide range of emotions as well as experiencing discomfort and pain. You may find the symptoms to be an inconvenience to your daily activities. In AMAB individuals with PUS, sexual activity may be impacted due to difficulties with ejaculation or erectile dysfunction. 

Discuss your concerns with your GP as they can discuss treatment options and help mitigate the impact of PUS on your daily life.

Recovery and Prognosis 

Post-Treatment Care

After surgery, your healthcare provider will discuss how to practice post-treatment care to avoid the recurrence of PUS. They may also schedule follow-up appointments to monitor your condition and manage possible complications early.

Long-Term Outlook

The prognosis and outlook can vary between individuals based on the severity of the stenosis, your general health, the effectiveness of treatments and any underlying conditions. Recovery time may be longer if the procedure performed to correct your urethra was complex. 

Prevention and Management Strategies 

PUS can be prevented and managed by adopting certain lifestyle changes including:

• Practising safe sex 
• Staying hydrated by drinking lots of fluids
• Avoid injury especially around the pelvic area by following health and safety procedures and wearing protective gear
• Prompt treatment of UTIs

FAQs

What is the difference between urethral stricture and stenosis?

These terms are used interchangeably, both often referring to the same condition.

What is the difference between anterior and posterior urethral strictures?

Urethral stricture in the anterior region affects the mid to lower urethra (referred to as spongy urethra). However, a stricture in the posterior region means that the narrowing is present between the constricting part of the bladder and the upper section of the urethra (known as the membraneous urethra). This division based on the urethra region is used in AMAB individuals.¹

How common is urethral stenosis?

Urethral stenosis affects mostly AMAB people and is predicted to affect about 0.9% of these individuals in industrialised countries.³

Summary 

Posterior urethral stenosis is a condition affecting the normal flow of urine exiting the body. The urethra is narrowed and is commonly caused by trauma near the pelvis or receiving treatments for prostate cancer. 

You may feel pain in your abdomen or notice blood in your urine which are signs that will need to be addressed with your GP. You may be directed to a urologist for a series of diagnostic tests. The most common tool is ureteroscopy, where a thin tube is inserted into the urethra for examination.

If you are diagnosed with PUS, you may have surgical interventions to correct the stenosis, allowing the normal flow of urine. To prevent PUS, adopt some lifestyle changes like staying hydrated and practising safe sex.